If the Cubs are going to give Z a big contract, they need to do more money per year but over fewer years than what Zito got. I don't know what's going to happen with Z over the next few years, but if you look at his PECOTA comps, there are a whole lot of guys who, like Z, had thrown a lot of innings prior to their age 26 seasons. Most of those guys had drastic drops in IP sometime between 26 and 29. Remember that a lot of pitchers peak early, and often teams get a pitcher's best years before they're eligible for free agency. I'm not saying the Cubs shouldn't re-sign Z; I'm just pointing out that there's an element of risk.